Along with indisputable advantages the optical pyrometry has over the other measuring meathods, and in particular, over the measuring method based on the use of thermocouple elements immersed in a melt (which enables continuously controlling the temperature, contactlessly effecting the measuring process etc.) it has a number of disadvantages which manifest itself under operating conditions. Thus, the measurement accuracy of pyrometers depends to a great extent on the optical properties of a radiating surface and intermediate medium.
One of the promising trends in optical pyrometry used in measuring the temperature of molten metals is the development of methods which are based on the use of light guides which form an insulated channel for transmitting thermal radiation from a melt to a pyrometer, thereby making it possible to reduce the influence of the above factors on the measurement accuracy. To enhance the efficiency of such light guides they are incorporated in light guide units which are mounted in the lining of a metallurgical vessel so that one end of the light guide is exposed to the melt and the other one is brought out to a pyrometer.
However, providing a light-guide unit, having a high operational reliability and satisfactory optical features which would ensure an improved measurement accuracy and wherein the light guides could be used repeatedly, is a problem the specialists in this field encounter in their attempts to develop such a light-guide unit.